Intraocular lenses are lens implants or artificial lenses to replace the natural lenses of a human eye. They are in particular used to replace the lenses of an eye affected by cloudiness (cataract) of the lens. By surgery, the affected lenses are removed and the intraocular lenses are inserted. Insertion into the eye is accomplished by means of a so-called injector, for example. It is important in this context that the surgical incision through which an intraocular lens is implanted is as small as possible (e.g. about 3 mm). This provides for the fastest possible healing process without complication and possibly also avoids the need for suture.
To be able to implant intraocular lenses which generally have a diameter of about 5 to 6 mm, the lenses must be foldable so as to fit through the small incision of about 3 mm. An injector for folding and inserting a folded lens into a human eye is described in International patent application WO 00/45746 A1, for example. The content of this patent application is fully incorporated into the present patent application by reference.
An injector is described therein for implanting and inserting a temporarily folded intraocular lens, which injector can be used to insert the folded lens into the capsula of the lens of the eye through an incision of the required size of about 3 mm in the eye.
The injector comprises a body having a thicker insertion and holding part and a thinner injection tube on an injection side and a continuous axial opening as a transport channel. In addition, the injector comprises a slider arranged so as to be displaceable axially in the transport channel. Furthermore, the injector comprises a radial insertion opening in the insertion and holding part transversely relative to the axis of the transport channel, as an insertion channel for the lens. The insertion opening communicates with the continuous transport opening. In the insertion opening, the non-folded lens rests flat on a support surface for being transported and is retained by a retaining rib extending longitudinally and centrally to the lens. The retaining rib is a plate-shaped, radially extending folding rib which can be pressed radially into the transport channel, through the insertion opening, whereby the lens is completely inserted into the transport channel folded around the retaining rib.
The injector described therein ensures safe implantation of an intraocular lens into a human and/or animal eye. The loading of the injector or the insertion of the intraocular lens into the injector can only be done just before surgery, by the operating ophthalmologist or a supportive surgical nurse.
However, in order to be able to accurately insert the intraocular lens into the eye, it is necessary for the lens to be positioned as accurately as possible on the support surface so that the lens is precisely insertable into the transport channel by means of the folding rib.
If the lens is not loaded sufficiently precisely, this may result in an undesired rotation of the lens when the lens is folded and inserted into the transport channel by means of the folding rib. Under certain circumstances, the lens may even be clamped between the folding rib and the transport channel so as to become unusable.
Therefore, the loading done by the ophthalmologist or surgical nurse presents a potential risk. Moreover, the lens previously stored in a package under sterile conditions may be contaminated when being removed from the package and placed in the injector.